5 ms·

Perhaps a stupid question, but... what are the risks? Wolndn't extracting too much energy from the earth's core cool it down, at least a little bit? Or does it

Perhaps a stupid question, but... what are the risks? Wolndn't extracting too much energy from the earth's core cool it down, at least a little bit? Or does it contain so much energy that extracting it to replace all of 'surface generation' won't make even a little difference?

whatshisface 2y ago
We can't drill anywhere near the mantle, geothermal extracts energy from the upper part of the crust.
- archon1410 2y ago
  Wouldn't drawing energy from the crust cool it down, and wouldn't a cooler crust in turn 'draw' more heat from the lower layers? I guess the earth already radiates out a lot of energy, the process of extracting geothermal energy will presumably lead it to radiate more energy. I don't know by how much though, or if it will make any real difference, or if that's how it even works.
numpad0 2y ago
Earthquakes! There are couple comments mentioning "fracking" around, that's destabilizing the land by injecting acid to get energy out. The acid is dangerous, and so are breaking up soil deep down.
__turbobrew__ 2y ago
I guess if you could extract enough energy from the core it would reduce convection which would in turn reduce the strength of the earth’s magnetic field.
tylerhou 2y ago
> Wouldn't extracting too much energy from the earth's core cool it down, at least a little bit? The earth generates ~50 terawatts of energy through radiation/other processes, while global energy consumption over the last year was 0.003 terawatts. I think we're fine.
- lurk2 2y ago
  Where are you getting 0.003 terawatts? Another user elsewhere in the thread[0] claimed "Global total energy (not just electricity) consumption is currently 180,000TWh/year, or about 20TW." Google is showing me other figures like 25,000 terawatt hours of electricity consumption annually. [0] - https://news.ycombinator.com/item?id=43234856 https://news.ycombinator.com/item?id=43234856
  - tylerhou 2y ago
    Oops, I missed the thousands. So 3 TW, which is larger, going by Google stats, and 20 TW by the other users. So that's not negligible.
  - boxed 2y ago
    One might also be careful to count energy properly. The fossil fuel industry has been counting "total energy" including losses to make fossil look bigger and harder to replace. But a gas car throws away like 70% of the energy, so going electric, you don't need the same energy to run the car. Not even close.
renewiltord 2y ago
Look at a cross section of the Earth: https://www.britannica.com/science/oceanic-crust https://www.britannica.com/science/oceanic-crust The deepest bore of all time was 12 km deep. The crust is between 5 km and 100 km and thinnest under the ocean. The numbers involved here are staggering. One might as well hope to stop the Earth's winds with a windmill.
Paradigma11 2y ago
I saw a documentary about some long running geothermal projects and basically the temperature in the well cooled down and made it uneconomical. They said they would have to wait, I think, 30 years for it to heat up again.

whatshisface 2y ago

We can't drill anywhere near the mantle, geothermal extracts energy from the upper part of the crust.

archon1410 2y ago
Wouldn't drawing energy from the crust cool it down, and wouldn't a cooler crust in turn 'draw' more heat from the lower layers? I guess the earth already radiates out a lot of energy, the process of extracting geothermal energy will presumably lead it to radiate more energy. I don't know by how much though, or if it will make any real difference, or if that's how it even works.

numpad0 2y ago

Earthquakes! There are couple comments mentioning "fracking" around, that's destabilizing the land by injecting acid to get energy out. The acid is dangerous, and so are breaking up soil deep down.

__turbobrew__ 2y ago

I guess if you could extract enough energy from the core it would reduce convection which would in turn reduce the strength of the earth’s magnetic field.

tylerhou 2y ago

> Wouldn't extracting too much energy from the earth's core cool it down, at least a little bit? The earth generates ~50 terawatts of energy through radiation/other processes, while global energy consumption over the last year was 0.003 terawatts. I think we're fine.

lurk2 2y ago
Where are you getting 0.003 terawatts? Another user elsewhere in the thread[0] claimed "Global total energy (not just electricity) consumption is currently 180,000TWh/year, or about 20TW." Google is showing me other figures like 25,000 terawatt hours of electricity consumption annually. [0] - https://news.ycombinator.com/item?id=43234856 https://news.ycombinator.com/item?id=43234856
- tylerhou 2y ago
  Oops, I missed the thousands. So 3 TW, which is larger, going by Google stats, and 20 TW by the other users. So that's not negligible.
- boxed 2y ago
  One might also be careful to count energy properly. The fossil fuel industry has been counting "total energy" including losses to make fossil look bigger and harder to replace. But a gas car throws away like 70% of the energy, so going electric, you don't need the same energy to run the car. Not even close.

renewiltord 2y ago

Look at a cross section of the Earth: https://www.britannica.com/science/oceanic-crust https://www.britannica.com/science/oceanic-crust The deepest bore of all time was 12 km deep. The crust is between 5 km and 100 km and thinnest under the ocean. The numbers involved here are staggering. One might as well hope to stop the Earth's winds with a windmill.

Paradigma11 2y ago

I saw a documentary about some long running geothermal projects and basically the temperature in the well cooled down and made it uneconomical. They said they would have to wait, I think, 30 years for it to heat up again.